We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
28
6
avatar

Find the sum 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + ... + 301 + 302.  (The pattern of signs is + + - - + + - - ...)

 Dec 3, 2019
 #1
avatar+978 
+2

1+2-3-4 = -4

5+6-7-8 = -4

And so on. 

Find the number of -4's

 Dec 3, 2019
edited by CoolStuffYT  Dec 3, 2019
 #2
avatar
0

Evaluate the terms whenever one + + - - occurs.

 

For example.

 

1 + 2 - 3 - 4 = -4

 

5 + 6 - 7 - 8 = -4

 

Then find how many +  + - - s are there

 Dec 3, 2019
 #3
avatar
0

i am clacuser not lgged in

Guest Dec 3, 2019
 #4
avatar+978 
+1

Hey calcuser

CoolStuffYT  Dec 3, 2019
 #5
avatar+2505 
0

yup the next 3 week will be a tornado

CalculatorUser  Dec 3, 2019
 #6
avatar+23575 
+2

Find the sum 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + ... + 301 + 302.  
(The pattern of signs is + + - - + + - - ...)

 

\(\begin{array}{|rll|} \hline && 1 \\ && \underbrace{+2 - 3}_{-1} \underbrace{ - 4 + 5}_{+1}\\ && \underbrace{ + 6 - 7}_{-1} \underbrace{ - 8 + 9}_{+1} \\ && + \ldots \\ && \underbrace{+298 - 299}_{-1} \underbrace{-300 + 301}_{+1} \\ && + 302 \\ &=& 1+0+302 \\ &=& \mathbf{303} \\ \hline \end{array} \)

 

laugh

 Dec 3, 2019

23 Online Users

avatar
avatar
avatar